Diplovertebron, genus of extinct amphibians of North America and Europe known from fossils in Late Carboniferous rocks (from 318 million to 299 million years ago). Diplovertebron represents an early representative of the anthracosaurs, a group of tetropods with some reptile traits. Since they could not produce an amniotic egg, which is a defining characteristic of true reptiles, anthracosaurs are classified as reptilelike amphibians. Diplovertebron and other primitive anthracosaurs are characterized by a distinctively constructed vertebral column and skull pattern and five-toed feet.